Journal of Applied Chemical Research
Volume:13 Issue: 4, Summer 2019

The need to elimination heavy metal from aqueous solutions cannot be over emphasized.Very studies have investigated the removal heavy metal from water. In this study a new magnetic nanocomposite of PEI on magnetized Sawdust (SD/MNP/PEI) was prepared. Investigations were conducted to study the adsorption behavior of heavy metal Zn (II) on the SD/MNP/PEI nanocomposite in aqueous medium by varying parameters such as contact time, pH, and initial metal concentration. Zn (II) adsorption was broadly dependent of pH. Isotherm data demonstrate that the Langmuir adsorption model was the best-suited model for this study. The results confirmed the good adsorption capacity of the new magnetic nanocomposite for the removal of Zn (II) from aqueous solutions and its great potential for practical applications.

An efficient method for the synthesis of mono and bulky 1,8-dioxooctahydroxanthenes was developed by the reaction of dimedone or 1,3-cyclohexadione and aldehydes or some bisaldehydes in the presence of polyvinylpolypyrrolidone supported oxalic acid (PVPP-OXA) as a new polymeric catalyst in ethanol at room temperature. Polyvinylpolypyrrolidone supported oxalic acid was characterized by FT-IR, and TGA analysis. Clean methodologies, simple preparation of the catalyst, high yields, environment-friendly and reusable catalyst are some advantages of this work.

Atomoxetine, an attention-deficit/hyperactivity disorder (ADHD) agent , has severe adverse effects, which even causes suicidal ideation in patients and when combined with other drugs such as monoamine oxidase inhibitors or in patients with cardiovascular disorders or pheochromocytoma, it can be fatal. In order to monitor the trough level of the drug, sensitive analytical methods are in demand.Therefore, for detection of trace levels of this drug, the trend solvent bar microextraction method coupled with HPLC-UV were implemented. Application of pH gradient of 10.3 and 3.0 (donor and acceptor phase, respectively) enabled preconcentration and microextraction of the target analyte. The results were modeled using Artificial Neural Network (ANN) successfully.The optimum results were obtained with a stirring rate of  365 rpm and salt addition by 15.1% at 25°C after 26 min. The limit of detection and quantification were 7.0 ng mL-1and 20  ng mL-1, respectively. It offered good linearity range of 20-5000 ng mL-1 with a coefficient of estimation higher than 0.9972 and a preconcentration factor of 112. The relative standard deviations of analysis were 4.6% within a day (n=3) and 6.2% between days (n=9).Overall, this method can be employed for several purposes such as for dosage adjustment in ADHD patients, clean validation in the pharmaceutical industry, and for trace determination in forensics.

Mo(III), Fe(III), Cd(II), Zn(II), Cu(II) complexes based on Tris[2-salicylaldeneimino)ethyl]amine (H3saltren) have been successfully synthesized. Newly prepared compounds have been characterized by 1H-NMR, 13C-NMR, IR and UV–VIS spectroscopy techniques. The spectral studies confirmed the ligand coordinates the metal ion to form complex via the oxygen and nitrogen atoms of the phenolic group and azomethine group. The antioxidant activity of the ligand and its complexes were determined by DPPH (2,2-diphenyl-1-picryl-hydrazyl) method in vitro. The obtained IC50 value of the DPPH activity for the copper complex (IC50 = 55.30 mg/ml) was higher than other compounds. Furthermore, the antimicrobial effects of the tested compounds have been tested against the bacterial species, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus by Disc diffusion and Micro-broth dilution methods. It has been found that the Cu complex has more effective against Bacillus cereus and the Cd complex showed the best antibacterial activity against the Staphylococcus aureus.

Arapid, highly sensitive and efficient flotation/magnetic stirring-assisted liquid-liquid microextraction combined with flame atomic absorption spectrometry has been proposed for the preconcentration and quantitative analysis of trace amounts of cadmium (II) in the presence of sodium diethyldithiocarbamateas complexingagent. Parameters including sample pH, concentration of the complexingagent, volume of extraction solvent, extraction time and aeration time were screened by a Plackett–Burman design and optimal conditions were obtained using a Box-Behnken design. At optimum conditions, the limit of detection and relative standard deviation (n=7, C=20 µg L−1) were 0.16 µg L-1 and 1.39%, respectively. Furthermore, a linear dynamic range of 0.5-80 µg L−1and enrichment factor of 152 were obtained. The accuracy of the method was evaluatedusing the analysis of certified reference material. Finally, the proposed techniquewas successfullyusedfor the determination of trace amounts of cadmium (II) in water and cereal samples.

Oxidation of formaldehyde (HCHO) is very important, owing to its use in fuel cells. Modification of electrodes surfaces is an excellent way to decrease the overpotentials as well as to increase the current density of the voltammetric response.pt as most efficient metal catalyst can easily be poisoned by product of oxidation and also it has high cost. In this work an efficient and low cost electrocatalytic system for electrochemical oxidation of formaldehyde in alkaline solution is introduced. For preparation of this modified electrode, copolymeric film on the surface of carbon paste electrode was formed by successive potential cycling in solution containing o-aminophenol and aniline as monomer and Triton X-100 as a surfactant. Ni(II) ions were incorporated into the electrode surface by immersion of the copolymeric modified electrode in 0.1 M Ni(II) ion solution. The influences of different parameters such as mol ratio of monomers in copolymer formation and the number of potential cycling for copolymer formation on electrocatalytic ability of the modified electrode for formaldehyde oxidation have been investigated and optimized.Results show that modified electrode with copolymeric films, show higher catalytic effect for formaldehyde oxidation respect to pure homopolymers (polyaniline or poly(o-aminophenol)). Also addition of Triton -X100 in electropolymerization step, considerably increased catalytic ability of the modified electrode for formaldehyde oxidation. This modified electrode displays a highly efficient electrocatalytic activity toward oxidation of formaldehyde. The current density of 11 mA cm-2 is greater than most of the previously reported electrodes.

An eco-safe and facile multi-component domino reaction has been described for the synthesis of 1H-pyrazolo [1, 2-b] phthalazine-5, 10-dione derivatives. The products were obtained by a four-component condensation reaction between phthalimide, hydrazine monohydrate, aromatic aldehyde derivatives and malononitrile in the presence of a catalytic amount of copper (II) oxide (CuO) under solvent-free conditions in high yields. The advantages of this one-pot procedure is environmentally friendly, efficient and economic availability of the catalyst, short reaction times, solvent-free conditions and clean reaction profiles.

Dyes are widely used in various industries, since theirdirect discharge to nature can cause many biological and environmental problems. Some of these dyes are toxic, carcinogenic and can cause skin and eye irritation. There are various dye removal techniques, but Adsorption found to be very effective and cheap method among the all available dye removal methods. The purpose of this study was to investigate the adsorption of C.I. Acid Red 1 (AR1)dye pollutant to sunflower seed shells (SSS) and pine cones(PC) as agro waste materials, to find out the optimalconditions formajor operational parameters such as contact time, adsorbent dosage, initial dye concentration and pH. The results showed that the optimal conditions for decolorization of the solution containing 40 mg/L AR1,by SSS and PC adsorbentswith removal efficiency of 84.2% and 74.47%, respectively, were obtained at100 min of contact time and pH= 2 at room temperature.Optimal value of adsorbent dosage for SSS and PC was determined 2.6 and 3.2 g/L, respectively.The physicochemical properties of the adsorbent were studied using various descriptive techniques such as FTIR, SEM, and BET.The adsorption process of both adsorbents was best fitted to Freundlich modeland followed pseudo-second-order rate kinetics.